1. Field of the Invention
The present invention relates to a semiconductor memory device, and more particular to a semiconductor memory device having a structure of memory cell arrays stacked on a semiconductor substrate.
2. Description of the Related Art
In recent years, attention has been focused on resistive memories as successive candidates for flash memories. The resistive memory devices include a resistive memory (ReRAM: Resistive RAM) in a narrow sense, which uses a transition metal oxide as a recording layer to nonvolatilely store the resistance value state thereof, and a phase change memory (PCRAM: Phase Change RAM), which uses a chalcogenide or the like as a recording layer to utilize the resistance value information on the crystalline state (conductor) and the amorphous state (insulator).
A variable resistor in the resistive memory has been known to have two types of operation modes. One is designed to switch the polarity of the applied voltage to set a high-resistance state and a low-resistance state. This is referred to as the bipolar type. The other is designed to control the voltage value and the voltage applying time without switching the polarity of the applied voltage. This is referred to as the unipolar type.
The unipolar type is preferable to realize a high-density memory cell array. This is because in the unipolar type a variable resistor and a rectifier such as a diode can be stacked at an intersection of a bit line and a word line to configure a cell array with the use of no transistor. Further, such cell arrays can be stacked and arrayed three-dimensionally to realize a high capacity without increasing the cell array area.
Generally, in a semiconductor memory, a bit line in a memory cell array is connected to a column-related control circuit including a bit line selector and a sense amplifier. In addition, a word line in the memory cell array is connected to a row-related control circuit including a row decoder and a word line driver. The semiconductor memory having a structure of three-dimensional memory cell arrays of the cross-point type, such as the resistive memories, stacked on a semiconductor substrate has a subject on how efficiently these control circuits can be arranged beneath the memory cell array to minimize the chip area.
Mark Johnson et al., “512-Mb PROM with a three-dimensional array of diode/antifuse memory cells”, IEEE Journal of Solid-State Circuits, November 2003, Vol. 38, No. 11, p. 1920-1928 discloses an arrangement of only one of the column-related control circuit or the row-related control circuit beneath one memory block in a semiconductor memory including memory blocks having the memory cell array structure stacked on a semiconductor substrate. The column-related control circuit or the row-related control circuit beneath the memory block is used to control a memory block located above or a memory block adjacent thereto.